KUnit tests for decoding extended 64 bit timestamps that verify the seconds part of [a/c/m] timestamps in ext4 inode structs are decoded correctly. KUnit tests, which run on boot and output the results to the debug log in TAP format (http://testanything.org/). are only useful for kernel devs running KUnit test harness. Not for inclusion into a production build. Test data is derive from the table under Documentation/filesystems/ext4/inodes.rst Inode Timestamps.

Signed-off-by: Iurii Zaikin yzaikin@google.com --- fs/ext4/Kconfig | 14 +++ fs/ext4/Makefile | 1 + fs/ext4/inode-test.c | 239 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 254 insertions(+) create mode 100644 fs/ext4/inode-test.c

diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig index cbb5ca830e57..f13dde8ed92b 100644 --- a/fs/ext4/Kconfig +++ b/fs/ext4/Kconfig @@ -106,3 +106,17 @@ config EXT4_DEBUG If you select Y here, then you will be able to turn on debugging with a command such as: echo 1 > /sys/module/ext4/parameters/mballoc_debug + +config EXT4_KUNIT_TESTS + bool "KUnit tests for ext4" + select EXT4_FS + depends on KUNIT + help + This builds the ext4 KUnit tests, which run on boot and output + the results to the debug log in TAP format (http://testanything.org/). + Only useful for kernel devs running KUnit test harness. Not for + inclusion into a production build. + For more information on KUnit and unit tests in general please refer + to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index b17ddc229ac5..a0588fd2eea6 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -13,4 +13,5 @@ ext4-y := balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \

ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o ext4-$(CONFIG_EXT4_FS_SECURITY) += xattr_security.o +ext4-$(CONFIG_EXT4_KUNIT_TESTS) += inode-test.o ext4-$(CONFIG_FS_VERITY) += verity.o diff --git a/fs/ext4/inode-test.c b/fs/ext4/inode-test.c new file mode 100644 index 000000000000..3b3a453ff382 --- /dev/null +++ b/fs/ext4/inode-test.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit test of ext4 inode that verify the seconds part of [a/c/m] + * timestamps in ext4 inode structs are decoded correctly. + */ + +#include <kunit/test.h> +#include <linux/kernel.h> +#include <linux/time64.h> + +#include "ext4.h" + +/* binary: 00000000 00000000 00000000 00000000 */ +#define LOWER_MSB_0 0L +/* binary: 01111111 11111111 11111111 11111111 */ +#define UPPER_MSB_0 0x7fffffffL +/* binary: 10000000 00000000 00000000 00000000 */ +#define LOWER_MSB_1 (-0x80000000L) +/* binary: 11111111 11111111 11111111 11111111 */ +#define UPPER_MSB_1 (-1L) +/* binary: 00111111 11111111 11111111 11111111 */ +#define MAX_NANOSECONDS ((1L << 30) - 1) + +#define CASE_NAME_FORMAT "%s: msb:%x lower_bound:%x extra_bits: %x" + +struct timestamp_expectation { + const char *test_case_name; + struct timespec64 expected; + u32 extra_bits; + bool msb_set; + bool lower_bound; +}; + +static time64_t get_32bit_time(const struct timestamp_expectation * const test) +{ + if (test->msb_set) { + if (test->lower_bound) + return LOWER_MSB_1; + + return UPPER_MSB_1; + } + + if (test->lower_bound) + return LOWER_MSB_0; + return UPPER_MSB_0; +} + + +/* + * These tests are derived from the table under + * Documentation/filesystems/ext4/inodes.rst Inode Timestamps + */ +static void inode_test_xtimestamp_decoding(struct kunit *test) +{ + const struct timestamp_expectation test_data[] = { + { + .test_case_name = + "1901-12-13 Lower bound of 32bit < 0 timestamp, no extra bits.", + .msb_set = true, + .lower_bound = true, + .extra_bits = 0, + .expected = {.tv_sec = -0x80000000LL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "1969-12-31 Upper bound of 32bit < 0 timestamp, no extra bits.", + .msb_set = true, + .lower_bound = false, + .extra_bits = 0, + .expected = {.tv_sec = -1LL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "1970-01-01 Lower bound of 32bit >=0 timestamp, no extra bits.", + .msb_set = false, + .lower_bound = true, + .extra_bits = 0, + .expected = {0LL, 0L}, + }, + + { + .test_case_name = + "2038-01-19 Upper bound of 32bit >=0 timestamp, no extra bits.", + .msb_set = false, + .lower_bound = false, + .extra_bits = 0, + .expected = {.tv_sec = 0x7fffffffLL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2038-01-19 Lower bound of 32bit <0 timestamp, lo extra sec bit on.", + .msb_set = true, + .lower_bound = true, + .extra_bits = 1, + .expected = {.tv_sec = 0x80000000LL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2106-02-07 Upper bound of 32bit <0 timestamp, lo extra sec bit on.", + .msb_set = true, + .lower_bound = false, + .extra_bits = 1, + .expected = {.tv_sec = 0xffffffffLL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2106-02-07 Lower bound of 32bit >=0 timestamp, lo extra sec bit on.", + .msb_set = false, + .lower_bound = true, + .extra_bits = 1, + .expected = {.tv_sec = 0x100000000LL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2174-02-25 Upper bound of 32bit >=0 timestamp, lo extra sec bit on.", + .msb_set = false, + .lower_bound = false, + .extra_bits = 1, + .expected = {.tv_sec = 0x17fffffffLL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2174-02-25 Lower bound of 32bit <0 timestamp, hi extra sec bit on.", + .msb_set = true, + .lower_bound = true, + .extra_bits = 2, + .expected = {.tv_sec = 0x180000000LL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2242-03-16 Upper bound of 32bit <0 timestamp, hi extra sec bit on.", + .msb_set = true, + .lower_bound = false, + .extra_bits = 2, + .expected = {.tv_sec = 0x1ffffffffLL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2242-03-16 Lower bound of 32bit >=0 timestamp, hi extra sec bit on.", + .msb_set = false, + .lower_bound = true, + .extra_bits = 2, + .expected = {.tv_sec = 0x200000000LL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2310-04-04 Upper bound of 32bit >=0 timestamp, hi extra sec bit on.", + .msb_set = false, + .lower_bound = false, + .extra_bits = 2, + .expected = {.tv_sec = 0x27fffffffLL, .tv_nsec = 0L}, + }, + + { + .test_case_name = +"2310-04-04 Upper bound of 32bit>=0 timestamp, hi extra sec bit 1. 1 ns bit 1.", + .msb_set = false, + .lower_bound = false, + .extra_bits = 6, + .expected = {.tv_sec = 0x27fffffffLL, .tv_nsec = 1L}, + }, + + { + .test_case_name = +"2378-04-22 Lower bound of 32bit>= timestamp. Extra sec bits 1. ns bits 1.", + .msb_set = false, + .lower_bound = true, + .extra_bits = 0xFFFFFFFF, + .expected = {.tv_sec = 0x300000000LL, + .tv_nsec = MAX_NANOSECONDS}, + }, + + { + .test_case_name = + "2378-04-22 Lower bound of 32bit >= timestamp. All extra sec bits on.", + .msb_set = false, + .lower_bound = true, + .extra_bits = 3, + .expected = {.tv_sec = 0x300000000LL, .tv_nsec = 0L}, + }, + + { + .test_case_name = + "2446-05-10 Upper bound of 32bit >= timestamp. All extra sec bits on.", + .msb_set = false, + .lower_bound = false, + .extra_bits = 3, + .expected = {.tv_sec = 0x37fffffffLL, .tv_nsec = 0L}, + } + }; + + struct timespec64 timestamp; + int i; + + for (i = 0; i < ARRAY_SIZE(test_data); ++i) { + timestamp.tv_sec = get_32bit_time(&test_data[i]); + ext4_decode_extra_time(&timestamp, + cpu_to_le32(test_data[i].extra_bits)); + + KUNIT_EXPECT_EQ_MSG(test, + test_data[i].expected.tv_sec, + timestamp.tv_sec, + CASE_NAME_FORMAT, + test_data[i].test_case_name, + test_data[i].msb_set, + test_data[i].lower_bound, + test_data[i].extra_bits); + KUNIT_EXPECT_EQ_MSG(test, + test_data[i].expected.tv_nsec, + timestamp.tv_nsec, + CASE_NAME_FORMAT, + test_data[i].test_case_name, + test_data[i].msb_set, + test_data[i].lower_bound, + test_data[i].extra_bits); + } +} + +static struct kunit_case ext4_inode_test_cases[] = { + KUNIT_CASE(inode_test_xtimestamp_decoding), + {} +}; + +static struct kunit_suite ext4_inode_test_suite = { + .name = "ext4_inode_test", + .test_cases = ext4_inode_test_cases, +}; + +kunit_test_suite(ext4_inode_test_suite); -- 2.23.0.700.g56cf767bdb-goog